EP0397586B1 - Boiler section for low temperature heating boiler - Google Patents

Description

The present invention relates to a heating body for a so-called low temperature boiler and more particularly to a heating body making it possible to control the temperature of the flue gases.

• elles sont souvent difficiles à nettoyer,
• la production d'oxydes d'azote n'est pas négligeable,
• elles sont bruyantes dans certains cas.

Current boilers have a number of drawbacks:

• they are often difficult to clean,
• the production of nitrogen oxides is not negligible,
• they are noisy in some cases.

• . la fabrication industrielle nécessite des noyaux complexes,
• . en cas de défaut de fabrication tout l'ensemble est à changer.

Low-power monobloc boilers are already known at low temperatures. These have the following disadvantages:

• . industrial manufacturing requires complex cores,
• . in the event of a manufacturing defect, the entire assembly must be changed.

By way of example, reference is made to the document FR-A-2071754 which describes a boiler whose flues are open on the front face of the heating body in order to facilitate their cleaning. In addition, horizontal flues can include baffles or trays whose function is to slow the exit of gases. The main drawback of this boiler is that the front panel is not used to heat the water in the canals, resulting in a loss of energy from the front of the boiler.

A first object of the invention is to provide a heating body of a new type making it possible to overcome the above drawbacks while maintaining the cost price of the assembly.

To achieve these goals, the heating body according to the invention, which comprises a front face, a rear face, possibly one or two intermediate elements, a plurality of channels for the circulation of the heating water, a door being applied on a façade plan, is characterized in that the front façade participates in the exchange of calories between the fumes and the water. To do this, there is provided on the front facade a set of one or more trays occupying most of the front face, set back from an appropriate distance from the facade plane, said trays being equipped with pins directed towards the front plane and in that there is also provided at least one water circulation channel, applied against or forming a body with said plates on the one hand, and in contact with the hearth on the other hand and in that one further provides a cavity forming the front part of the hearth and a plurality of smoke flues, cavity and smoke flues opening on the one hand on the facade plane to facilitate cleaning, and on the other hand on the assembly plane of the parts facade or intermediate exchanger elements.

A second object of the present invention is to provide a heating body making it possible to produce a particularly efficient boiler in a reduced size, by lengthening the internal flue gas circuit and by increasing the exchange surfaces.

A third object of the present invention is to involve the front panel in the exchange of water / smoke heat.

Another object of the invention is to vary, by a suitable device, the outlet temperature of the fumes and to adjust this temperature according to the characteristics and needs of the chimney, in order to mainly avoid condensation therein. observed when the temperature of the fumes leaving the boiler turns out to be too low.

Flame temperature variators are already known such as that described in document FR-A-2017563, which acts on the length of the path of the fumes just before they leave the boiler. However, this boiler is higher than the usual boilers, because it comprises above the heating body a return chamber in which the variator is placed.

The variator according to the invention does not have this drawback, it consists of at least one plate, placed on the smoke path, in the space between the internal face of the door and the exchanger plates of the boiler, this plate being either applied to at least part of the pins of one of the exchanger plates, or fixed to the internal face of the boiler door; the variator can also be formed by two of these plates.

Two alternative embodiments of the temperature variator are proposed and described below.

• la figure 1 est une vue en élévation de la façade avant du corps de chauffe ;
• la figure 2 est une vue en élévation de la façade arrière du même corps de chauffe, objet de la description ci-après ;
• la figure 3 est une vue en coupe selon AA de la figure 1 ;
• la figure 4 est une vue en coupe selon BB de la figure 1 ;
• la figure 5 est un croquis montrant le parcours des fumées dans le corps de chauffe ;
• la figure 6 est une demi-vue de face de la face avant d'une chaudière équipée d'une première forme de réalisation d'un variateur de température conforme à l'invention ;
• la figure 7 est une vue en coupe selon CC de la figure 6 ;
• la figure 8 est une demi-vue de face de la face arrière de la chaudière équipée d'une deuxième forme de réalisation de variateur de température conforme à l'invention ;
• la figure 9 est une vue en coupe selon DD de la figure 8.

The invention will be better understood using the description below made with reference to the appended figures in which:

• Figure 1 is an elevational view of the front panel of the heater;
• Figure 2 is an elevational view of the rear facade of the same heater, object of the description below;
• Figure 3 is a sectional view along AA of Figure 1;
• Figure 4 is a sectional view along BB of Figure 1;
• FIG. 5 is a sketch showing the course of the fumes in the heating body;
• Figure 6 is a half front view of the front face of a boiler equipped with a first embodiment of a temperature controller according to the invention;
• Figure 7 is a sectional view along CC of Figure 6;
• Figure 8 is a half front view of the rear face of the boiler equipped with a second embodiment of the temperature controller according to the invention;
• FIG. 9 is a sectional view along DD of FIG. 8.

The cast iron heating body represented in the figures from 1 to 5 is preferably composed of two parts, a front face 1 and a rear face 2 assembled according to a vertical assembly plane P, by tie rods not shown placed in housings appropriate 9 and of the pairs which come to be housed in the connections.

The front facade has a central cavity 3 forming the front part of the hearth where the flame will develop. This cavity 3 opens onto the front facade plane 17 substantially following the general shape of a rhombus 31 with rounded angles. This cavity widens and opens into the plane "P" in a complex shape 32 shown in FIG. 1, the lower part of which is substantially the same shape and the same dimensions as the lower part of the form 31, and the upper part recalls the general shape of a rectangle with rounded angles occupying practically the width of the boiler.

Exchanger flues are provided in the lower and upper parts of the front panel, and are fitted with exchange fins 16 in a manner known per se.

Two horizontal lower flues 14a, 14b, in a direction perpendicular to the plane "P" or to the facade plane 17 have a substantially triangular rounded section whose side resembling a hypotenuse is directed towards the focal point and the angular part towards the outside of the body of the boiler.

Three horizontal upper flues 15a, 15b, 15 ′ in a direction perpendicular to the plane "P", show a section of substantially rectangular shape with rounded corners, the central flue 15 ′ having its narrow side towards the hearth 3 and, the lateral flues 15a 15b showing him their largest side.

The front façade also has two large exchanger plates 11, 12 parallel to the front façade plane 17 and recessed with respect to this plane by a distance "d".

The exchanger plates 11, 12 are equipped over their entire surface with pins or fins 13 increasing the exchange surface in known manner.

They extend over most of the facade, in any case over the entire area available between the lower flues 14a, 14b and upper 15b, 15b, and the front 31 of the hearth.

The rear facade 2 comprises a central cavity 33 forming the rear part of the hearth, this cavity does not open onto the rear of the boiler but it opens onto the plane "P" in a substantially rectangular shape 34, the upper part of which substantially affects the shapes and dimensions of the upper part of the form 32 of the front panel, and the lower part of which extends to the bottom of the heating body, as can be seen in FIG. 2.

The rear facade 2 comprises three flues 25a, 25b, 25 ′ in the upper part which are the extensions of the flues 15a, 15b, 15 ′ of the front facade.

A set of water circulation channels 4 is provided all around the fireplace and the flues. In particular two vertical channels 42 of L-shaped section (see FIG. 4), run along the exchanger plates 11,12 to capture the calories collected by said plates 11,12. The internal and concave wall 43 of each channel 42 looks entirely at the front part 3 of the hearth and at least part of the external wall 44 is applied to an exchanger plate or is integral with it.

The front facade is closed by a door 5 covering most of the plane 17 of the facade and closing both the central opening 31 and the five front flues 14a, 14b, 15b, 15 ′, 15a, for example the support door burner (described in patent application FR-A-2590003 with special hinges for opening on the right or on the left (patent application FR-A-2634542).

The rear facade is closed by the manifold 7 with central nozzle 71 provided for collecting the smoke from the flues 25a, 25b, 25 ′.

• parcours (I) horizontal vers le fond du foyer,
• séparation des fumées selon deux parcours (IIa, IIb) horizontaux, d'arrière en avant, dans les carneaux inférieurs 14a, 14b,
• ascension des fumées selon les parcours (IIIa, IIIb) le long des plateaux échangeurs se divisant respectivement au-dessus de la cavité 31 en (IVa, III′a) et en (IVb, III′b),
• aspiration d'avant en arrière par la cheminée selon des parcours (IVa, IVb, IV′) dans les carneaux 15a, 25a,15′,25′, ce dernier carneau collectant les fumées des parcours (III′a, III′b).

We will now refer to Figure 5 which shows the smoke path, it is a path with four paths referenced from I to IV:

• horizontal path (I) towards the bottom of the hearth,
• separation of smoke along two horizontal routes (IIa, IIb), from back to front, in the lower flues 14a, 14b,
• smoke ascent along the paths (IIIa, IIIb) along the exchanger plates dividing respectively above the cavity 31 in (IVa, III′a) and in (IVb, III′b),
• suction from front to back through the chimney along routes (IVa, IVb, IV ′) in the flues 15a, 25a, 15 ′, 25 ′, the latter flue collecting the smoke from the routes (III′a, III′b) .

The heating body which has just been described has been designed so that the vertical paths in the front panel are ascending, this arrangement has the function of creating a natural thermal draft and of reducing the overall pressure drop of the boiler.

As indicated, one of the peculiarities of the front facade concerns the presence of two plates 11, 12 fitted with pins or heat exchange fins directed towards the plane 17 of the facade, and the presence of a vertical circulation channel 42 of water by plate applied each against or forming a body with on the one hand each of said plates 11, 12 and in contact on the other hand with the hearth. Said circulation channels 42 are thus doubly heated: by the hearth and by the plates 11, 12 of the front facade 1.

The distance "d" between the plates 11, 12 and the front plane 17 is calculated as a function of the flow rate of the fumes and of the admissible pressure drops.

It will also be noted that all of the flues open onto the front plan 17, as does the foyer. This design has the function of facilitating cleaning: thus, when the door is opened, all surfaces licked by smoke, flues, trays, fireplace are directly accessible in full. In addition, the fins 16 of the flues are aligned and arranged so as to also facilitate cleaning.

On the other hand, the shape of the hearth gives it a large surface in relation to its volume, this design has the function of reducing the temperature of the flame and therefore the production of nitrogen oxides.

Optionally, one or more means of communication can be provided between the home and the route of the smoke (IIa, IIb) in the vicinity of the outlet of the lower flues 14a, 14b, either in the flues themselves, or in the trays 11,12. These communication means, for example simple holes 18, have the function of recycling part of the combustion gases, of reducing the rate of unburnt and improving the overall yield.

According to another option, a sound trap can be integrated in door 5 (patent application FR-A-2590003).

Also optional, there is the possibility of increasing the smoke outlet temperature, for example by providing a bypass 19 on the front panel to send hot gases from the hearth directly along and along paths III or IV, and / or by providing holes 26 on the rear facade between the hearth and the collector 7.

The present boiler can also benefit from the improvements described in patent applications FR-A-2547025 for the removal of condensates in the joint plane "P" for operation at low temperature, and in patent applications FR -A-2615591 and FR-A-2631421 published on 17.11.89 for adjustable feet.

In addition, by construction, large diameter connections 8 are provided for the installation of electrical resistances, and to allow dual-energy use of the boiler.

As a variant, it is of course possible to produce a boiler with four paths like the one which has just been described, the direction of circulation of which is reversed, that is to say with the smoke outlet from the hearth in the upper part, the smoke going down along the plates of the front facade and extraction in the lower part at the rear, but in this case, we would lose the advantage of the natural upward pull described above.

Another variant would be to equip the rear facade with trays similar to the trays 11,12 and functionally equivalent, this would increase the exchange surface but would increase the dimensions of the boiler.

According to a third variant, one or two intermediate exchanger elements can be provided, between the two front elements 1, 2 in order to increase the volume of the hearth and the power of the boiler.

• décaler latéralement le foyer, dans ce cas la chaudière comporte un plateau unique en façade avant;
• modifier la forme du foyer ;
• modifier le nombre et la forme technique des carneaux;
• modifier le nombre et la forme des canaux 42 prévus entre le foyer et le ou les plateaux 11,12.

Without departing from the principle of the invention, it is also possible:

• laterally shift the hearth, in this case the boiler has a single plate on the front;
• modify the shape of the fireplace;
• modify the number and technical form of the flues;
• modify the number and the shape of the channels 42 provided between the hearth and the plate or plates 11,12.

The boiler design which has just been described is particularly suitable for small boilers from 15 to 40 KW approximately and up to a hundred KW depending on the variants. This design can be applied to steel boilers.

The advantages of this boiler are a good volume-useful / power ratio, improved manufacturing and cost price, ease of maintenance, low nuisance (noise, nitrogen oxide).

The invention also relates to a flue gas temperature controller in the form of one or more plates, of adjustable surface, to be mounted on the heating body described above.

According to a first variant represented in FIGS. 6 and 7, the temperature variator consists of a plate, for example of cast iron P1 placed on one of the exchanger plates 11 or 12, and applied to the tips of the pins 13 by any means suitable fixing "S". By way of example, the fixing means shown "S" is a screw "R" with a square head, capable of withstanding the temperature of the fumes, associated with a vertical adjustment light "L" of the plate P1 allowing the positioning in height of said plate relative to the exchanger plate or to each exchanger plate.

The high position of P1 has been shown in solid lines and in its dashed lines in its low position.

It is likewise possible to provide a positioning in width of the plate by means of a horizontal light.

The plate P1 is for example substantially rectangular and has the function of improving the speed of the fumes in the path or paths of the fumes (IIIa, IIIb), situated on each side of the hearth in the space between the plates 11, 12 and the internal face of the door 5, therefore improving the heat exchanges with the water circulating in the channels 42 and lowering the temperature of the gases in the paths (IIIa, IIIb, IVa, IVb, IV ′) and in boiler outlet.

Depending on the shape and surface of the plate P1, the pins 13 can be partially or entirely covered with the same exchanger plate, the variation in the temperature of the boiler outlet gases can therefore be adjusted to the needs of the chimney and / or the standards in force.

In addition, it is possible to place two plates P1, one on each exchanger plate, in this case the temperature variator consists of two plates P1.

According to the second variant shown in FIGS. 8 and 9, the temperature variator consists of one or two plates P2 of refractory fibers, for example ceramic fibers or equivalent, fixed on the internal face of the door 5, on both sides and d 'other of the burner opening, by any suitable fixing means, for example screws "V" or a temperature-resistant adhesive. Plate P2 has the function of reducing the space "d" between pins and door and to improve the speed of the fumes and to decrease the temperature.

Each plate P2 can be rectangular (variant not shown) or have the shape of a "C", the concave part of which faces the opening of the hearth (variant of FIGS. 8 and 9).

One or more pre-cuts can be provided on P2, for example L1, L2 so that the installer of the boiler can easily reduce the surface area of the plates delivered with the boiler, and thus adjust the variation of the outlet temperature of the fumes.

One could also reduce the plates in their width, by providing vertical precut lines (not shown).

This alternative embodiment has the advantage of reducing the noise level of the boiler, in particular if two complete P2 plates are fixed or if the parts below the line L2 are kept at a minimum.

For example, we can obtain a reduction of the order of 20 ° to 30 ° by installing two complete P2 plates, then, if the outlet temperature is deemed too low, we can gradually remove one or two pieces of l 'one and / or the other plate P2 to increase the outlet temperature until disappearance of condensations in the chimney.

It must be clear that, based on the above, the adjustable useful surface as well as the location of the temperature controller plate (s) is or are chosen or modified by the installer when installing the boiler .

Claims (20)

1. Heating body for a boiler, comprising at least one front face element (1) and one rear face element (2) which, after assembly in a vertical plane (P), form on the one hand a passage for the hot gases and fumes from the furnace, where the flame develops, to the outlet manifold, which passage comprises horizontal flues, and on the other hand a water circulation circuit, the heat exchange surfaces between the two fluids being provided with points (13) or the equivalent, the said heating body also comprising a door (5) bearing against a vertical face plane (17) of the front face element (1), characterised in that the front face element (1) comprises:

   . at least one vertical exchange plate (11, 12) recessed behind the plane (17) of the face by a distance (d), each plate being provided with points (13) directed towards the plane (17) of the face so as to form, between the plane (17) of this face and the exchange plate or plates, a vertical volume occupying most of the front surface of the front face element, with the horizontal flues opening into this volume and a gas curtain circulating within it,

   . a means for varying the thickness of the said gas curtain,

   . at least one vertical water circulation duct (42), at least part of the outer wall (44) of which bears against the exchange plate or forms an integral part with it, while its internal wall is in contact with the furnace.
2. Heating body according to claim 1, characterised in that the number of vertical exchange plates is equal to two.
3. Heating body according to claims 1 or 2, characterised in that the fumes circulate upwards within the volume comprised between the plates (11, 12) and the plane (17) of the face closed by the door.
4. Heating body according to any one of the preceding claims, characterised in that the front face element is provided with:

   . two exchange plates (11, 12),

   . two lower horizontal flues (14a, 14b) in a direction which is perpendicular to the plane (17) of the face,

   . a central cavity (3), with the flues and the cavity opening, on the one hand, on to the plane (17) of the face and, on the other hand, on to the plane (P) of assembly.
5. Heating body according to claim 4, characterised in that the cavity (3) opens on to the plane (17) of the face according to a substantially rhombic shape (31) with rounded angles, flares out and opens on to the plane (P) according to a complex shape (32), the lower part of which has substantially the shape and dimensions of the lower part of the shape (31), and the top part of which has substantially the shape and dimensions of the top part of the shape (34) of the rear part (33) of the furnace.
6. Heating body according to any one of the preceding claims, characterised in that the front face (1) is provided with at least one means of communication (18) between the furnace and the outlet of the lower flues (14a, 14b).
7. Heating body according to any one of the preceding claims, characterised in that the rear face (2) is of the same type as the front face (1).
8. Heating body according to any one of the preceding claims, characterised in that each vertical water circulation duct (42) has an L-shaped cross section, the whole of the internal, concave wall (43) of which bears against the front part (3) of the furnace.
9. Temperature variator used in a heating body according to any one of claims 1 to 8, characterised in that it is formed by at least one removable plate (P1 or P2) with an adjustable surface area, arranged vertically in the passage for the fumes, within the vertical volume between the internal surface of the boiler door (5) and the exchange plates of the heating body.
10. Variator according to claim 9, characterised in that the plate (P1) is arranged on one of the exchange plates (11, 12) and bears against at least some of its points (13) by way of an attachment means (S).
11. Variator according to claim 9, characterised in that the plate (P2) is attached to the internal surface of the door (5).
12. Variator according to claim 10, characterised in that it comprises two plates (P1), one on each exchange plate.
13. Variator according to claim 11, characterised in that it comprises two plates (P2), one on each side of the opening of the burner.
14. Variator according to one of claims 10 or 12, characterised in that the refractory cast iron plate (P1) has a substantially rectangular shape and comprises an adjustment slot (L).
15. Variator according to one of claims 11 or 13, characterised in that the refractory fibre plate (P2) comprises at least one pre-cutting line (L₁, L₂).
16. Variator according to one of claims 11, 13 or 15, characterised in that the plate (P2) is in the shape of a "C", the concave part of which is oriented towards the opening of the furnace.
17. Variator according to any one of preceding claims 9 to 16, characterised in that the plates are rectangular.
18. Variator according to any one of preceding claims 9 to 17, characterised in that the adjustable useful surface of the plate or plates of the temperature variator is modified by the installer at the time of the installation of the boiler.
19. Variator according to any one of preceding claims 9 to 18, characterised in that the location of the plate or plates is chosen by the installer at the time of the installation of the boiler.
20. Variator according to any one of preceding claims 9 to 19, characterised in that the surface area of the plate or plates is chosen by the installer at the time of the installation of the boiler.

Images